Astronomy:2 Ceti
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Cetus |
| Right ascension | 00h 03m 44.38784s[1] |
| Declination | −17° 20′ 09.5719″[1] |
| Apparent magnitude (V) | 4.483[2] |
| Characteristics | |
| Spectral type | B9 IVn[3] |
| U−B color index | −0.12[4] |
| B−V color index | −0.047±0.003[5] |
| Astrometry | |
| Radial velocity (Rv) | +8.0±4.6[6] km/s |
| Proper motion (μ) | RA: +25.17[1] mas/yr Dec.: −9.16[1] mas/yr |
| Parallax (π) | 11.98 ± 0.26[1] mas |
| Distance | 272 ± 6 ly (83 ± 2 pc) |
| Absolute magnitude (MV) | −0.06[5] |
| Details | |
| Mass | 2.68±0.11[7] M☉ |
| Radius | 2.75[7] R☉ |
| Luminosity | 119+6 −5[8] L☉ |
| Surface gravity (log g) | 3.99±0.09[7] cgs |
| Temperature | 11,419±388[9] K |
| Metallicity [Fe/H] | +0.00±0.24[3] dex |
| Rotational velocity (v sin i) | 116[8] or 237[10] km/s |
| Age | 217[9] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
2 Ceti is a single[12] star in the equatorial constellation of Cetus, near the border with Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.483.[2] The distance to 2 Ceti can be estimated from its annual parallax shift of 12.0 mas,[1] which yields a value of around 272 light years. It appears to be moving further from the Earth with a heliocentric radial velocity of about +8 km/s.[6]
The stellar classification for this star is B9 IVn,[3] matching a B-type subgiant star with "nebulous" absorption lines due to rapid rotation.[13] Estimates of the rotation rate range from 116[8] to 237[10] km/s, and this high rate of spin is giving the star an equatorial bulge that is 12% larger than the polar radius.[13] 2 Ceti is about 217[9] million years old with 2.7[7] times the mass of the Sun and 2.75[7] times the Sun's radius. It is radiating 119[8] times the Sun's luminosity from its photosphere at an effective temperature of 11,419 K.[9] An infrared excess has been detected around this star by the Akari satellite at a wavelength of 18μm, suggesting there is an orbiting debris disk.[14]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007). "Validation of the new Hipparcos reduction". Astronomy and Astrophysics 474 (2): 653–664. doi:10.1051/0004-6361:20078357. Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 Høg, E. et al. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics 355: L27–L30. Bibcode: 2000A&A...355L..27H.
- ↑ 3.0 3.1 3.2 Wu, Yue et al. (2010). "Coudé-feed stellar spectral library – atmospheric parameters". Astronomy & Astrophysics 525: A71. doi:10.1051/0004-6361/201015014. Bibcode: 2011A&A...525A..71W.
- ↑ Nicolet, B. (1964). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics Supplement Series 34: 1–49. Bibcode: 1978A&AS...34....1N.
- ↑ 5.0 5.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 6.0 6.1 Gontcharov, G. A. (2006). "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system". Astronomy Letters 32 (11): 759–771. doi:10.1134/S1063773706110065. Bibcode: 2006AstL...32..759G.
- ↑ 7.0 7.1 7.2 7.3 7.4 Allende Prieto, C.; Lambert, D. L. (1999). "Fundamental parameters of nearby stars from the comparison with evolutionary calculations: masses, radii and effective temperatures". Astronomy and Astrophysics 352: 555–562. Bibcode: 1999A&A...352..555A.
- ↑ 8.0 8.1 8.2 8.3 Zorec, J. et al. (2012). "Rotational velocities of A-type stars. IV. Evolution of rotational velocities". Astronomy and Astrophysics 537: A120. doi:10.1051/0004-6361/201117691. Bibcode: 2012A&A...537A.120Z.
- ↑ 9.0 9.1 9.2 9.3 David, Trevor J.; Hillenbrand, Lynne A. (2015). "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets". The Astrophysical Journal 804 (2): 146. doi:10.1088/0004-637X/804/2/146. Bibcode: 2015ApJ...804..146D.
- ↑ 10.0 10.1 Royer, F. et al. (2007). "Rotational velocities of A-type stars". Astronomy and Astrophysics 463 (2): 671. doi:10.1051/0004-6361:20065224. Bibcode: 2007A&A...463..671R.
- ↑ "2 Cet". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=2+Cet.
- ↑ Chini, R. et al. (2012). "A spectroscopic survey on the multiplicity of high-mass stars". Monthly Notices of the Royal Astronomical Society 424 (3): 1925–1929. doi:10.1111/j.1365-2966.2012.21317.x. Bibcode: 2012MNRAS.424.1925C.
- ↑ 13.0 13.1 van Belle, Gerard T. (March 2012). "Interferometric observations of rapidly rotating stars". The Astronomy and Astrophysics Review 20 (1): 51. doi:10.1007/s00159-012-0051-2. Bibcode: 2012A&ARv..20...51V.
- ↑ Ishihara, Daisuke et al. (May 2017). "Faint warm debris disks around nearby bright stars explored by AKARI and IRSF". Astronomy & Astrophysics 601: 18. doi:10.1051/0004-6361/201526215. A72. Bibcode: 2017A&A...601A..72I.
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